If in blood or increased numbers in bone marrow:T-Lymphoblastic leukemia (T-ALL)Rarely some non-neoplastic conditions

› Classic Immunophenotype:

CD3+ (cytoplasmic)

CD7+

CD34+

TdT+

› Cartoon Image:

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› Misc:

Blasts cells cannot be reliably distinguished from each other based on morphology alone. The exception are blasts with Auer Rod(s) which are unique to abnormal Myeloblast {16}s and abnormal promyelocytes as noted in some AMLs and APL
Note: Abnormal lymphoblasts can show immunophenotypic abberancies (e.g. loss of T-cell antigens such as CD7, CD5 and CD2 or the gain of myeloid markers such as CD13, etc.)